This invention relates generally to a hermetically sealed dynamoelectric device such as, for example, an electric motor employed in a refrigeration compressor drive mechanism. More particularly, it relates to such a device which provides for using the liquid phase of a refrigerant for cooling, and using the gas phase for sealing.
In a hermetically sealed electric motor, it is conventional to use an externally supplied coolant to dissipate the heat generated by the resistance of the motor windings. In a typical refrigeration system, refrigerant is drawn from the condenser and separated into liquid and gas phases. The liquid phase is used to cool the rotor and stator elements of the motor. The gas phase is used to prevent leakage of lubricating oil past the motor bearing seals into the refrigerant circuit.
In this environment, it is important to protect the liquid from contact with the oil, although contact of the gas with the oil can be tolerated. Past efforts have been directed toward elaborate sealing arrangements for the bearings. The typical prior art cooling and sealing arrangements are effective but inefficient in providing adequate cooling, and are only partially effective in providing sealing.
Thus, there remains a need in the art for a hermetic dynamoelectric device with refrigerant cooling and sealing that exhibits improved operating characteristics. The device should be simple and inexpensive to construct, and should operate efficiently and reliably.